This invention relates generally as indicated to a tire press unloader and more particularly to an unloader for a press of the upstanding bladder type.
Various types of unloading devices for tire presses have been in use or known for a number of years. However, in curing presses which employ an upstanding bladder mechanism, removal of the tire is particularly difficult because of the presence of the bladder mechanism. Moreover, removal of the tire is further complicated by the post cure inflation of the tire after curing in that the tire must be properly presented to the post cure inflator (PCI) to insure automatic operation. In addition, the cured tire should be removed vertically from the bladder mechanism to minimize chances of a bead being caught by the top of the shaping bladder and being punched or kinked.
One type of curing press unloader which has solved the above-noted problems is illustrated in Barton et al U.S. Pat. No. 4,013,186. Although such unloader can properly perform the desired removal of the tire from the curing press, it employs a large number of moving parts and is somewhat complicated in operation. It would be desirable to provide an unloader with fewer moving parts and less complicated operation which can properly remove cured tires from presses.
Other types of unloaders employ complex cam slots for actuation of a tire platform or the like for removal of a tire from the curing press; however, such cam slots are difficult and expensive to machine and are subject to substantial wear requiring early replacement of the component which contains the cam slots. Moreover, adjustment of the platform lift height in such unloaders for different sizes of tire curing presses is difficult and oftentimes requires a new set of cam slots. One such type of unloader mechanism is illustrated in Yoshida et al U.S. Pat. No. 3,685,929 which employs a plurality of cooperating cam followers and complex guide grooves therefor to move a tire platform through a predetermined path to remove a tire from a tire curing press.
Other unloaders are shown in U.S. Pat. Nos. 2,832,991, 3,075,237; 3,222,716; 3,336,630 and 3,477,100.